I just updated to 2.6.33.07-pclos3 in LXDE 2010 and had no sound afterwards. Fixed it by going into
PCC> Hardware > Sound config > Advanced > Reset sound mixer to default values.
Sounds works for me again. Any one else had this problem or was it just me ?
I use onboard sound (Silicon Integrated Systems [SiS]|AC'97 Sound Controller w/ "snd_intel8x0")[ALSA] driver).